Editing History of Ukraine (section)

== Middle Ages ==
=== Early Slavs ===
{{main|Early Slavs}}
{{see also|Antes people|Rus' Khaganate}}
{{further|Slavic migrations to Southeastern Europe}}

Following the power vacuum left by the fall of [[Huns|Hunnic]] and [[Goths|Gothic]] dominance, the [[Early Slavs]] began to expand over much of the territory that is now Ukraine during the 5th century, continuing their migration into the [[Balkans]] in the 6th century. The exact origins of the Early Slavs remain uncertain, though several theories suggest they may have originated near the [[Polesia]] region, a marshy area between modern-day [[Belarus]] and [[Ukraine]]. This period marks a transition from the [[Kyiv culture]] to the establishment of Slavic tribes across Eastern Europe.<ref>{{Cite book |last=Barford |first=P. M. |title=The early Slavs: Culture and society in early medieval Eastern Europe |date=2001 |publisher=Cornell University Press |isbn=0-8014-3977-9 |page=32|location=Ithaca, NY |oclc=47054689}}</ref>

[[File:Slavarchaeology.png|thumb|left|Archaeological cultures associated with [[proto-Slavs]] and [[early Slavs]]: [[Chernoles culture]] (before 500 BC), [[Zarubintsy culture]] (300 BC to AD 100), [[Przeworsk culture]] (300 BC to AD 400), [[Korchak culture|Prague-Korchak horizon]] (6th to 7th century, Slavic expansion)]]
In the 5th and 6th centuries, the [[Antes people|Antes Union]] (a tribal confederation) is generally believed to have been situated in present-day Ukraine. The Antes are considered ancestors of several Slavic tribes that would later form the [[Ukrainians]], including the [[Polans (eastern)|Polans]], [[Severians]], [[Drevlians]], [[White Croats]], [[Dulebes]], [[Ulichs]], and [[Tivertsi]]. The migration of these tribes from Ukraine throughout the Balkans contributed to the foundation of several [[South Slavs|South Slavic]] nations, while northern migrations, reaching as far as [[Lake Ilmen]], gave rise to the [[Ilmen Slavs]], [[Krivichs]], and [[Radimichs]].<ref name="so">М. Грушевський – "Історія України". Том І, розділ IV, Велике слов'янське розселення: Історія Антів, їх походи, війна з Словянами, боротьба з Аварами, останні звістки, про Антів</ref>

The collapse of the Antes Union in 602, following a devastating raid by the [[Pannonian Avars]], led to a fragmentation of the early Slavic federation. Despite this, many of these tribes maintained their distinct identities until the formation of larger political entities in the early second millennium, such as [[Kievan Rus']], which began to consolidate Slavic lands.<ref name="so"/>

The Early Slavs were primarily agrarian, relying on subsistence farming, and lived in semi-nomadic communities. Over time, they developed a complex social structure, with local chieftains leading tribal groups. They also practiced [[paganism]], with a pantheon of gods tied to nature, such as [[Perun]] (god of thunder) and [[Dazhbog]] (sun god). By the time of the Antes Union's decline, the cultural and religious practices of the Slavs had already begun to influence neighboring peoples, laying the groundwork for the Slavic cultural sphere that would emerge later in Eastern and Southeastern [[Europe]].<ref>[https://bigenc.ru/ethnology/text/3625013 Slavs] / Ilya Gavritukhin, [[Vladimir Petrukhin]]. // Saint-Germain World 1679-Social security [Electronic resource]. - 2015. - pp. 388-389 — - ([[Great Russian Encyclopedia]] : [in 35 volumes] / ch. ed. Yuri Osipov; 2004-2017, vol. 30) — - ISBN 978-5-85270-367-5.</ref>

=== Arrival of the Bulgars and Khazars ===
{{Main|Old Great Bulgaria|Khazar Khaganate}}

In the 7th century, the territory of modern Ukraine was at the core of the state of the [[Bulgars]], often referred to as [[Old Great Bulgaria]]. This state, with its capital at [[Phanagoria]] (located in what is now the Taman Peninsula), controlled a significant part of the northern [[Black Sea]] region. The Bulgars, a semi-nomadic people from [[Central Asia]], were known for their sophisticated society, military organization, and far-reaching influence.<ref name="history of ukraine27"/>

[[File:Old_Great_Bulgaria.svg|thumbnail|Approximate territory of Old Great Bulgaria]]
By the end of the 7th century, the Bulgars faced increasing pressure from neighboring tribes and empires. Most of the Bulgar tribes migrated in various directions—some settled in the [[Balkans]], where they eventually established the [[First Bulgarian Empire]]. Other groups moved towards the Volga region, forming [[Volga Bulgaria]], which became a prominent center of trade and culture. The remaining parts of Old Great Bulgaria were eventually absorbed by the [[Khazars]], another semi-nomadic people from Central Asia.<ref name="history of ukraine27"/>

The Khazars founded the [[Khazar Khaganate]], a powerful and influential state near the [[Caspian Sea]] and the [[Caucasus (geographic region)|Caucasus]]. The Khaganate's territory expanded to include parts of modern-day western [[Kazakhstan]], eastern [[Ukraine]], southern [[Russia]], and northern [[Azerbaijan]]. The Khazars were noted for their religious tolerance and political pragmatism, famously adopting [[Judaism]] as their state religion in the 8th century, although [[Christianity]], [[Islam]], and other faiths were also practiced within their borders.<ref>{{Cite encyclopedia| title = Khazar| encyclopedia = Encyclopedia Britannica| url = https://www.britannica.com/topic/Khazar | url-status = live| archive-url = https://web.archive.org/web/20220302083101/https://www.britannica.com/topic/Khazar| date = 29 March 2020 | archive-date = 2 March 2022 | access-date = 30 July 2024}}</ref>

The Khazars played a key role in the politics and economy of [[Eastern Europe]] and the [[Pontic–Caspian steppe]]. Their control over trade routes contributed to the establishment of the ''[[Pax Khazarica]]'', a period of relative peace and stability that fostered safe long-distance trade. This stability allowed traders, including the [[Radhanite]] Jews, to operate along vast routes that stretched from [[China]] to the [[Byzantine Empire]]. These trade routes facilitated the exchange of goods, culture, and ideas across [[Eurasia]].<ref name="Akıncı 2019 pp. 1123–1135">{{cite journal | last=Akıncı | first=Meltem | title=Pax Khazarica | journal=History Studies: International Journal of History | volume=11 | issue=4 | date=31 August 2019 | issn=1309-4688 | doi=10.9737/hist.2019.756 | pages=1123–1135| doi-access=free }}</ref>

=== Kievan Rus' (9th century–1240) ===
{{Main|Kievan Rus'}}

==== Origin and foundation of state ====
[[File:Laurentian Codex 01 Rus land.jpg|left|thumb|"Rus' land" from the ''[[Primary Chronicle]]'', a copy of the [[Laurentian Codex]]]]
The origins of the Kievan state and the etymology of its name, Rus', continue to be subjects of scholarly debate. One theory, often called the '[[Norman theory]]', posits that the term Rus' originated from the [[Scandinavia]]n [[Varangians]], who were active in trade and military ventures across [[Eastern Europe]] in the early medieval period. Proponents of this theory argue that the Varangians, also known as the Rus', initially brought a political and military influence that shaped the emerging state structure, with the term Rus' eventually becoming synonymous with the region and its people.<ref>{{Cite book |last=Hosking |first=Geoffrey |title=Russia and the Russians: A History |publisher=Harvard University Press |year=2001 |pages=30}}</ref>

In contrast, the '[[Anti-Normanism|anti-Norman theory]]' suggests that the term Rus' has indigenous [[Slavic languages|Slavic]] roots, developing independently of Scandinavian influence. Advocates of this theory assert that [[East Slavs|Eastern Slavic tribes]] already had established political and social frameworks before any contact with the Varangians, and that these tribes were naturally progressing toward political consolidation. According to this perspective, the name Rus' could be linked to the [[Ros (river)|Ros River]], a historically significant waterway flowing through present-day [[Ukraine]], which was home to various Slavic communities. In this view, Rus' may have referred to a collective identity tied to a specific geographic region or a union of native tribes, rather than to foreign invaders or rulers.<ref>''Encyclopedia.com'', [https://www.encyclopedia.com/history/encyclopedias-almanacs-transcripts-and-maps/normanist-controversy "Normanist Controversy"]</ref><ref>{{cite encyclopedia|url=https://www.encyclopediaofukraine.com/display.asp?AddButton=pages%5CR%5CU%5CRushDA.htm|title=The name of Rus'|encyclopedia=Encyclopedia of Ukraine|access-date=16 December 2021}}</ref>

[[File:Царьград.jpg|thumb|The Rus' under the walls of Constantinople]]
The first reliable mention of the Rus' dates back to the year 839 in the [[Franks|Frankish]] chronicle ''[[Annals of St. Bertin]]'', where members of an embassy from the north, arriving in the [[Byzantine Empire]], referred to themselves as Rus'.<ref>{{harvtxt|Garipzanov|2006|loc=p. 7}}</ref> The second notable mention of the Rus' occurred in 860, when they launched a bold and unexpected [[Siege of Constantinople (860)|naval raid]] on [[Constantinople]]. Commanding a fleet across the [[Black Sea]], the Rus' forces struck at the very heart of the [[Byzantine Empire]], quickly reaching the city’s outskirts. According to accounts from [[Greeks|Greek]] eyewitnesses, the Rus' not only managed to pillage the suburbs of Constantinople but also instilled widespread fear among its residents. The Byzantine defenses were unprepared, allowing the Rus' to withdraw without significant resistance.<ref>''History Explained'', [https://historyexplained.org/the-viking-siege-of-constantinople-860-the-rus-first-strike-on-byzantium/ "Siege of Constantinople (860): The Rus' First Strike on Byzantium"]</ref>

The earliest source about the history of the [[Dnieper Ukraine]] region is the ''[[Tale of Bygone Years]]'' (or ''Primary Chronicle''), written no earlier than the 11th century. In its 'legendary' part, it narrates the Rus' raid on Constantinople and the formation of a state centered in [[Kiev]] during the second half of the 9th century. The Chronicle, in particular, mentions the names of the leaders of the raid on Constantinople — [[Askold and Dir]] — and calls them retainers of the Scandinavian [[Rurik dynasty]]. According to the Chronicle, a representative of this dynasty, [[Oleg the Wise]], allegedly came to Kiev from [[Novgorod]] in 882, killed Askold and Dir, and took control of the Kiev state. This narrative contains chronological errors—for example, it incorrectly dates the Constantinople raid to 867—and lacks corroboration from archaeological evidence, which suggests that Novgorod itself was only established in the 10th century. Therefore, modern historians view the Chronicle's account of the 9th century as largely speculative and likely a later construction by the Chronicle's author.{{sfn|Cross|Sherbowitz-Wetzor|1953|p=61}}{{sfn|Ostrowski|2018|p=44}}

[[File:Historic core of Rus'.png|thumb|left|''Rus' land'' in the narrow sense<ref name=":3">{{Cite journal |last=Motsia |first=Oleksandr |date=2009 |title=|script-title=uk:«Руська» термінологія в Київському та Галицько-Волинському літописних зводах |trans-title="Ruthenian" question in Kyiv and Halych-Volyn annalistic codes |url=http://dspace.nbuv.gov.ua/bitstream/handle/123456789/5284/02-Motsya.pdf |journal=Arkheolohiia |issue=1 |pages= |doi=10.6084/M9.FIGSHARE.1492467.V1 |issn=0235-3490 |access-date=25 January 2023 |archive-date=2 February 2014 |archive-url=https://web.archive.org/web/20140202101523/http://dspace.nbuv.gov.ua/bitstream/handle/123456789/5284/02-Motsya.pdf |url-status=live}}</ref>
{{legend|LightSalmon|1. After [[Petro Tolochko]]}}
{{legend|Yellow|2. After A.&nbsp;M. Nasonov}}
{{legend|LimeGreen|3. After [[Boris Rybakov]]}}]]
Scholars associate the state-building processes in the Middle Dnieper region with the emergence of the well-known trade route from Scandinavia to Constantinople, known as the '[[Route from the Varangians to the Greeks]]'. A significant section of this route ran along the [[Dnieper River]], and Kiev was an important transshipment point, allowing control over trade along the Dnieper, [[Pripyat]], and [[Desna (river)|Desna]] rivers.<ref>{{cite encyclopedia|url=https://www.britannica.com/place/Dnieper-River|title=Dnieper River|access-date=7 September 2012|encyclopedia=[[Encyclopædia Britannica]]}}</ref> The Middle Dnieper region began to serve as a political, cultural, and economic center for the East Slavic world. It eventually came to be known as the ''Rus' land'' in the narrow sense of this term.<ref name=":3" /> According to ''The Tale of Bygone Years'', the East Slavic tribe of the [[Polans (eastern)|Polans]], inhabitants of the Middle Dnieper region, adopted the name ''Rus''' for their land and were regarded as the most advanced among the East Slavs. Thus, they played a central role in forming a new tribal union centered around Kiev.{{sfn|Duczko|2004|page=207}}

From the first half of the 10th century, the first confirmed ruler of the Kievan state, as documented in foreign sources, was [[Igor the Old]], whom the ''Primary Chronicle'' identifies as a prince. Information in the Chronicle regarding governance during this period is considered relatively reliable. The princely retinue played a significant role in governance, accompanying rulers on campaigns and collecting tribute from subjugated local [[Slavic tribes]]. The collected tribute (such as [[furs]], [[honey]], [[Hide (skin)|hides]], [[wax]], and [[Slavery|slaves]]) was mainly [[slavery in the Byzantine Empire|exported to Byzantium]], with the proceeds used to purchase [[weapon]]s, [[luxury goods]], and [[wine]]—constituting the core of imports. When trade conditions no longer met the prince's expectations, he led an unsuccessful campaign against Constantinople in 941, which eventually resulted in a new [[Rus'–Byzantine Treaty (945)|Rus-Byzantine trade treaty]] in 944. The ''Tale of Bygone Years'' recounts Igor's attempt to levy additional tribute from the subdued Slavs, which led to a rebellion by the [[Drevlians]], who killed him in 945.<ref name="korosten">
{{cite web|url=http://www.geocities.com/korostencity/iskorosten.htm |title=Korosten (Iskorosten): A small town with a great history |publisher=geocities.com |date=27 February 2008 |access-date=16 February 2014 |last=Tarasenko |first=Leonid |url-status=dead |archive-url=https://web.archive.org/web/20091026051916/http://geocities.com/korostencity/iskorosten.htm |archive-date=26 October 2009 }}</ref>

[[File:Radzivill Olga in Konstantinopol.jpg|thumb|The baptism of [[Olga of Kiev|Olga]] in [[Constantinople]]]]
Following Igor's death in 945, his widow, [[Princess Olga]], assumed the role of regent for their young son, [[Sviatoslav I|Sviatoslav]], who was still too young to rule. Olga is best known for her calculated and fierce retaliation against the Drevlians, a campaign that culminated in the annexation of their lands into the expanding Kievan Rus'. Olga also implemented significant reforms, particularly by restructuring the tribute collection system known as ''[[poliudie]]''. This new system made revenue collection more systematic and centralized, reducing the likelihood of rebellion by ensuring a more balanced distribution of power. In a landmark decision, Olga became the first ruler of Kievan Rus' to embrace [[Christianity]] around 957 during a diplomatic visit to Constantinople. However, despite her conversion, the state under her rule remained predominantly pagan, with Christianity gaining influence only later under her descendants.{{sfn|Cross|Sherbowitz-Wetzor|1953|pp=79–80}}{{sfn|Gasparov|Raevsky-Hughes|2018|pp=77–81}}

When Sviatoslav assumed rule over Kievan Rus', he launched an ambitious military expansion. His most notable achievement was the decisive defeat of the [[Khazar Khaganate]], a once-dominant regional power that had controlled key trade routes for centuries. The fall of the Khazars opened opportunities for Kievan Rus' to extend its influence into the Caucasus and beyond. In addition to his campaigns in the east, Sviatoslav waged numerous battles against the [[Byzantine Empire]], seeking to establish Kievan Rus' as a formidable power in the [[Balkans]]. His primary goal was to create a lasting base in [[First Bulgarian Empire|Bulgaria]], strengthening his strategic position in southeastern Europe. However, his ambitions in the Balkans were thwarted after a Byzantine counterattack. In 972, while returning from his Balkan campaign, Sviatoslav was ambushed and killed by the [[Pechenegs]] near the Dnieper River.{{sfn|Stephenson|2000|p=56}}{{sfn|Curta|2019|p=296}}

[[File:Оплакивание и погребение Олега Святославича у города Овруча.jpg|left|thumb|Death of Oleg in [[Ovruch]]]]
After Sviatoslav's death, a power struggle ensued among his sons. [[Yaropolk I of Kiev|Yaropolk]], Sviatoslav's eldest son, assumed the title of [[Grand Prince of Kiev]] and worked to consolidate power across the vast territory, leading to conflicts with his brothers. [[Oleg of Drelinia|Oleg]], Sviatoslav's second son, governed the Drevlian lands, and rivalry between him and Yaropolk escalated into open warfare. During one of their clashes around 977, Oleg was killed, further intensifying the conflict. Initially, [[Vladimir the Great|Vladimir]], Sviatoslav's youngest son, fled to avoid being entangled in the conflict. However, after Oleg's death, he returned with a Varangian army. By 980, Vladimir had defeated Yaropolk and consolidated power, becoming the sole ruler of Kievan Rus'.<ref name="Hanak">{{cite book |last1=Hanak |first1=Walter K. |title=The Nature and the Image of Princely Power in Kievan Rus', 980-1054: A Study of Sources |date=10 October 2013 |publisher=BRILL |isbn=978-90-04-26022-1 |page=15 |url=https://books.google.com/books?id=WfV0AQAAQBAJ |language=en}}</ref>

==== Golden Age and Christianisation ====
{{Main|Christianization of Kievan Rus'}}
{{Further|History of Christianity in Ukraine}}

During the reign of Vladimir the Great, Kievan Rus' expanded significantly, notably through the conquest and annexation of [[Red Ruthenia]], [[Transcarpathia]], and [[Chersonesus|Korsun]]. These territorial gains made Kievan Rus' the largest state in [[Europe]] at the time, covering over 800,000 square kilometers and boasting a population of more than 5 million. The socio-economic structure of Kievan Rus' was similar to that of other European states of the period, characterized by a natural economy, communal land ownership, and reliance on slash-and-burn agriculture, and animal husbandry.<ref>{{cite encyclopedia|url=https://www.britannica.com/topic/Kyivan-Rus|title=Kievan Rus. Medieval State, Europe, Culture & Religion|access-date=25 October 2024|encyclopedia=[[Encyclopædia Britannica]]}}</ref>

[[File:58-manasses-chronicle.jpg|thumb|Christianization of Kievan Rus']]
Vladimir reformed local governance by abolishing the traditional tribal autonomies and installing his own appointed governors, further centralizing his authority. Under his rule, Kiev emerged as one of the wealthiest commercial centers in Europe during the 10th and 11th centuries, benefiting from its strategic location on trade routes and its growing political influence. Initially, Vladimir supported the [[Slavic paganism|worship of Slavic deities]] such as [[Perun]]. However, in 988, he made a historic decision to [[Christianization of Kievan Rus'|convert Kievan Rus']] to [[Christianity]], adopting [[Eastern Orthodoxy]] from the [[Byzantine Empire]]. He personally led the mass baptism of the people of Kiev in the [[Pochaina (river)|Pochaina River]] and built the first stone church in Kievan Rus' — [[Church of the Tithes]]. He also introduced the ''Charter on Church Courts and Tithes'', thereby securing a strong relationship between the church and state. Unlike the earlier attempts of his grandmother, Princess Olga, Vladimir's reforms had a lasting impact, deeply influencing the religious and cultural development of the region.<ref name="Enc Kiëv">{{cite encyclopedia |title=Kiëv; Rusland §2. Het Rijk van Kiëv |encyclopedia=Encarta Encyclopedie Winkler Prins |date=2002 |publisher=Microsoft Corporation/Het Spectrum |language=nl}}</ref>

Vladimir's rule also saw administrative, monetary, and military reforms. He appointed governors and entrusted his sons with ruling major cities, also minted his own [[Money of Kievan Rus'#Zolotnik|gold]] (Zlatnik) and [[Money of Kievan Rus'#Srebrenik|silver]] (Srebrenik) coins, and granted borderlands to loyal vassals in exchange for military defense. To protect the realm, Vladimir oversaw the construction of an extensive system of defensive fortifications, known as the [[Serpent's Wall]]s, which stretched for 1,000 kilometers, safeguarding Kievan Rus' from external threats.<ref name="ehukuchera">Kuchera, M. ''[http://resource.history.org.ua/cgi-bin/eiu/history.exe?&I21DBN=EIU&P21DBN=EIU&S21STN=1&S21REF=10&S21FMT=eiu_all&C21COM=S&S21CNR=20&S21P01=0&S21P02=0&S21P03=TRN=&S21COLORTERMS=0&S21STR=Zmievi_valy Serpent Walls (ЗМІЄВІ ВАЛИ)]''. Encyclopedia of History of Ukraine.</ref>

[[File:Daughters of Yaroslav the Wise.jpg|left|thumb|11th-century fresco of [[Saint Sophia Cathedral, Kyiv]], representing the daughters of Yaroslav I]]
Despite these accomplishments, Kievan Rus' entered a turbulent period of internal strife following Vladimir's death in 1015, as his sons fought for control. This era of internecine conflict lasted until 1019, when [[Yaroslav the Wise]] emerged victorious and assumed the throne. Ruling jointly with his brother [[Mstislav of Chernigov|Mstislav]] until 1036, Yaroslav presided over what is often regarded as the golden age of Kievan Rus'. One of Yaroslav's key achievements was his decisive defeat of the [[Pechenegs]], who had long been a threat to the state. To commemorate this victory, Yaroslav ordered the construction of the [[Saint Sophia Cathedral, Kyiv|Saint Sophia Cathedral]] in Kiev, a structure that still stands as a symbol of this prosperous era. He also founded the [[Kyiv Pechersk Lavra]] and supported the election of  [[Hilarion of Kiev]] as the [[List of metropolitans and patriarchs of Kyiv|Kyiv Metropolitan]], marking a significant step in the independence of the Kievan church. Yaroslav's reign was also notable for the introduction of the first written legal code — ''[[Russkaya Pravda|Rus' Truth]]'', which established a foundation for legal governance in the state. Additionally, Yaroslav engaged in extensive marriage diplomacy, forming alliances by arranging marriages between his daughters and European royalty.<ref>{{cite web |url=https://www.britannica.com/EBchecked/topic/652106/Yaroslav-I |title=Yaroslav I (prince of Kiev) – Encyclopædia Britannica |publisher=Britannica.com |date=22 May 2014 |access-date=7 August 2014 |archive-date=17 October 2014 |archive-url=https://web.archive.org/web/20141017153710/http://www.britannica.com/EBchecked/topic/652106/Yaroslav-I |url-status=live}}</ref>{{sfn|Plokhy|2006|p=13}} However, after Yaroslav's death, Kievan Rus' began to fragment, as his sons divided the territory among themselves, leading to further internecine conflicts and the eventual decline of centralized power.{{sfn|Katchanovski|Kohut|Nesebio|Yurkevich|2013|p=1}}

==== Feudal fragmentation ====
{{See also|Council of Liubech}}

The feudal fragmentation of Kievan Rus' began in the late 11th century, driven by a complex interplay of internal and external factors. One significant factor was the rotational succession system, allowing power to pass among male relatives instead of directly from father to son. This system often sparked conflicts, as competing claims to power emerged. With princes often granted specific territories, autonomous principalities began to emerge clearly. Regional cities such as [[Chernihiv]], [[Polotsk]], and [[Novgorod]] gained power and asserted their independence, with local elites increasing their influence. By this time, the authority of the [[Grand Prince of Kiev]] was notably weakening. Regional princes, bolstered by local resources and armies, began to resist central control. Additionally, the vast geography and economic diversity of Rus' impeded unity, as various regions developed their own trade routes and systems. External threats from nomadic groups, such as the [[Pechenegs]] and [[Polovtsy]] ([[Cumans]]), further exacerbated regionalism, compelling local rulers to focus on defending their territories.<ref>''Кучкин В. А.'' [http://www.runivers.ru/vestnik/issues/8004/457285/ О времени существования Древнерусского государства (историография вопроса)] {{Webarchive|url=https://web.archive.org/web/20180124070810/http://www.runivers.ru/vestnik/issues/8004/457285/ |date=24 січня 2018 }}</ref><ref>''Котляр Н.Ф''. [http://www.al24.ru/wp-content/uploads/2015/03/кот_11.pdf Удельная раздробленность Руси.] {{Webarchive|url=https://web.archive.org/web/20180712204506/http://www.al24.ru/wp-content/uploads/2015/03/кот_11.pdf |date=12 липня 2018 }}&nbsp;— К.: Институт истории Украины НАН Украины, 2013.&nbsp;— 270 с.</ref>

[[File:I zjazady książąt Rusi Kijowskiej. Brąz, granit. 1997 Lubecz, Ukraina.jpg|thumb|Monument in Liubech by [[Giennadij Jerszow]]]]
After Yaroslav the Wise's death, his sons divided the lands, which significantly accelerated political fragmentation. Although his succession plan aimed to prevent conflict, it ultimately sowed the seeds of feudal division. The [[Council of Liubech]], convened by several princes, including [[Vladimir II Monomakh|Vladimir Monomakh]], sought to settle disputes and clarify the inheritance of principalities. This agreement formalized Kievan Rus's division into regional hereditary principalities, thereby legalizing fragmentation. The adage "Let everyone hold his own" emerged, signifying that each prince would govern his own territory without interference from others.<ref>{{Cite web |date=17 August 2023 |title=Любечский съезд 1097 |url=https://bigenc.ru/c/liubechskii-s-ezd-1097-60ed5e |access-date=6 January 2024 |website=Большая российская энциклопедия |language=ru}}</ref>

Vladimir Monomakh, who served as Grand Prince of Kiev from 1113 to 1125, is remembered as one of Kievan Rus' most capable leaders. He ascended the throne amid internal strife and external threats, yet worked diligently to stabilize the fragmented territories of Rus'. Monomakh's reign achieved relative unity through efforts to reduce feuds among princes and reinforce central authority. His military successes, particularly against the Polovtsy (Cumans), secured the region's borders. Diplomatically, he forged strong ties with Europe, notably through his marriage to [[Gytha of Wessex]], the daughter of English [[King Harold II]]. As an educated ruler, Monomakh authored ''The Instruction of Vladimir Monomakh'', offering insights on governance, morality, and leadership. His reign is often regarded as one of the last periods of unity before Rus' descended further into division.<ref name=RBA>Рыбаков Б. А. [http://lib.ru/HISTORY/RYBAKOW_B_A/russ.txt Рождение Руси] {{Webarchive|url=https://web.archive.org/web/20170907015132/http://lib.ru/HISTORY/RYBAKOW_B_A/russ.txt |date=7 Вересня 2017 }}</ref>{{sfn|Mason|2004|p=200}}

Monomakh's son, [[Mstislav I of Kiev|Mstislav the Great]], preserved some unity during his reign from 1125 to 1132. However, following his death, the principality fractured. The division of lands among Monomakh's sons and other relatives resulted in multiple competing power centers.<ref>Извлеченіе изъ древнихъ Русскихъ л?тописей / Отделъ І. Изв?стія л?тописные // Сборникъ матеріаловъ для исторической топографіи Кіева и его окрестностей.&nbsp;— К. : типографія Е.&nbsp;Я.&nbsp;Федорова, 1874.&nbsp;— С. 16.</ref><ref>{{cite book |last1=Dimnik |first1=Martin |title=The dynasty of Chernigov. 1054-1146 |date=1994 |publisher=Pontifical Institute of Mediaeval Studies |location=Toronto |isbn=0888441169 |page=389}}</ref> The process of feudal fragmentation marked a turning point in the history of Rus', culminating in its eventual decline and the rise of smaller, more independent states. These would later evolve into the medieval powers of the [[Kingdom of Ruthenia]], the [[Principality of Polotsk]], the [[Novgorod Republic]], and others.<ref>{{cite journal |last=Kollmann |first=Nancy |title=Collateral Succession in Kievan Rus |journal=Harvard Ukrainian Studies |year=1990 |volume=14 |pages=377–387}}</ref><ref>Самсонова М. Н. Рогволод и Рогнеда: скандинавские корни полоцкой княжеской династии // Alba Ruscia: белорусские земли на перекрестке культур и цивилизаций (X—XVI вв.) (Серия «Исторические исследования».) — М.: Квадрига, 2015. /Отв. ред. А. В. Мартынюк. — 256 с. — С. 25—26.</ref><ref>Michael C. Paul, "Was the Prince of Novgorod a 'Third-rate bureaucrat' after 1136?" ''Jahrbucher fur Geschichte Osteuropas'' 56, No. 1 (Spring 2008): 72–113.</ref><ref>{{citation |url=https://books.google.com/books?id=mMoFBAAAQBAJ&q=The+Sack+of+Kiev+of+1169%3A+Its+Significance+for+the+Succession+to+Kievan+Rus%27&pg=PA323 |title=The Emergence of Russia 750–1200 |first1=Simon |last1=Franklin |first2=Jonathan |last2=Shepard |pages=323–324 |publisher=Routledge |date=1996 |isbn=978-1-317-87224-5 |access-date=14 November 2020 |archive-date=23 April 2023 |archive-url=https://web.archive.org/web/20230423152840/https://books.google.com/books?id=mMoFBAAAQBAJ&q=The+Sack+of+Kiev+of+1169%3A+Its+Significance+for+the+Succession+to+Kievan+Rus%27&pg=PA323 |url-status=live}}</ref>

==== Mongol invasion of Kievan Rus' ====
{{Main|Mongol invasion of Kievan Rus'}}

[[File:Siege_of_Kiev_(1240).png|left|thumb|Imaginative portrayal of the 1240 Siege of Kiev in the 16th-century ''[[Facial Chronicle]]'']]
In 1222, a new wave of nomads—the warlike [[Mongols]]—arrived in the [[Black Sea]] steppes and defeated the [[Cumans|Polovtsians]] as part of the [[Mongol Empire]]'s westward expansion. The Polovtsians, who had family ties with the Rus' princes, turned to Rus' for help. A joint Rus'-Polovtsian force marched into the steppes, where the [[Battle of the Kalka River]] took place in 1223. Following the battle, the Mongols retreated eastward for approximately 15 years.<ref>{{Cite web|url=http://resource.history.org.ua/cgi-bin/eiu/history.exe?&I21DBN=EIU&P21DBN=EIU&S21STN=1&S21REF=10&S21FMT=eiu_all&C21COM=S&S21CNR=20&S21P01=0&S21P02=0&S21P03=TRN=&S21COLORTERMS=0&S21STR=Kalka_bytva_1223|title=КАЛКА, БИТВА НА РІЧЦІ 1223|website=resource.history.org.ua|access-date=1 July 2024}}</ref>

In the late 1230s, the Mongols returned with significantly larger forces under the leadership of [[Batu Khan]] and his general [[Subutai]]. The Mongols first attacked the eastern regions of the state, using superior siege tactics to overwhelm local defenses. Between 1239 and 1240, the Mongols shifted their focus to the southern territories. In 1240, they laid [[Siege of Kiev (1240)|siege to Kiev]], which ultimately fell after a brutal assault, marking the final collapse of Kievan Rus' as a unified political entity.<ref>{{Cite book |last=Plokhy |first=Serhii |title=The gates of Europe: A history of Ukraine. |publisher=Basic Books |year=2015 |isbn=9780465050918 |location=New York |pages=48–52}}</ref><ref>{{cite encyclopedia |title=Rusland §2. Het Rijk van Kiëv |encyclopedia=Encarta Encyclopedie Winkler Prins |date=2002 |publisher=Microsoft Corporation/Het Spectrum |language=nl}}</ref>

As a result of this invasion, Kievan Rus' was extensively destroyed, depopulated, and fragmented. Following their conquest, the Mongols established dominion over the region through the [[Golden Horde]], transforming most of the Rus' principalities into tributary states. Under Mongol rule, the Rus' were required to pay heavy taxes and submit to Mongol authority. The invasion severely stunted the region's political, cultural, and economic development, and the effects of Mongol domination reverberated for centuries. Despite its devastation, the [[Eastern Orthodox Church]] played an important role in preserving cultural identity during Mongol rule.<ref name="Mongol Conquests">McEvedy, Colin (1978). [http://users.erols.com/mwhite28/warstat0.htm#Mongol "Mongol Conquests"] ''Atlas of World Population History''</ref><ref>{{Cite web |date=26 August 2011 |title=Археологические исследования показали, что Свислочь в 100 км юго-восточнее Минска была подвергнута монгольскому нашествию 1237—1240 годов. |trans-title=Archaeological studies have shown that Svisloch, 100 km southeast of Minsk, was subjected to the Mongol invasion of 1237–1240. |url=http://news.tut.by/society/244031.html |archive-url=https://web.archive.org/web/20110826032555/http://news.tut.by/society/244031.html |archive-date=26 August 2011 |access-date=7 April 2023 |website=}}</ref>

==== Kingdom of Galicia–Volhynia ====
{{Main|Kingdom of Galicia–Volhynia}}

The Principality—later the [[Kingdom of Galicia–Volhynia]] ([[Ruthenia]])—emerged from the disintegration of [[Kievan Rus']]. Its rulers continued the political and cultural legacy of Kiev, preserving the traditions and governance of the Rus' state even as Kiev fell to [[Mongol]] control.<ref name = "Pelenski">[https://books.google.com/books?id=iuFB8V2X4yEC&pg=PA9 Jarosław Pelenski.] In P. Potichnyj (ed.) (1992). ''Ukraine and Russia in their historical encounter.'' Edmonton, Alberta: Canadian Institute of Ukrainian Studies Press, University of Alberta. pp.8–15</ref><ref>{{Cite web|url=http://resource.history.org.ua/cgi-bin/eiu/history.exe?&I21DBN=EIU&P21DBN=EIU&S21STN=1&S21REF=10&S21FMT=eiu_all&C21COM=S&S21CNR=20&S21P01=0&S21P02=0&S21P03=TRN=&S21COLORTERMS=0&S21STR=Korolivstvo_Rus|title=КОРОЛІВСТВО РУСЬ|website=resource.history.org.ua|access-date=1 July 2024}}</ref> Previously, [[Vladimir the Great]] had established the cities of [[Halych]] and [[Volodymyr-Volynskyi|Volodymyr]] as regional capitals, setting the foundation for future political entities in the region. The area was originally inhabited by the [[Dulebes]], [[Tivertsi]], and [[White Croats]] tribes.<ref name="Sedov">{{cite book |first=Valentin Vasilyevich |last=Sedov |year=2013 |orig-year=1995 |script-title=ru: Славяне в раннем Средневековье |title=Sloveni u ranom srednjem veku |trans-title=Slavs in Early Middle Ages|url=https://books.google.com/books?id=HD4oAAAAMAAJ |language=ru |publisher=Akademska knjiga |location=Novi Sad |isbn=978-86-6263-026-1 |pages=41–44, 164, 388, 428–430, 435–437, 481, 497, 499, 515}}</ref> Initially, [[Volhynia]] and [[Galicia (Eastern Europe)|Galicia]] existed as separate principalities, each ruled by descendants of [[Yaroslav the Wise]]. Galicia was governed by the [[Rostislav of Tmutarakan|Rostislavich]] dynasty, while Volhynia was initially ruled by the [[Igor Yaroslavich|Igorevichs]] and eventually by the [[Iziaslav II of Kiev|Iziaslavich]] dynasty.{{Sfn|Magocsi|2010|p=123}} During the reign of [[Yaroslav Osmomysl]] (1153–1187), Galicia expanded its influence, extending as far as the Black Sea.{{Sfn|Magocsi|2010|p=123}}

Rivalry between the rulers of these principalities often revolved around efforts to assert dominance over one another. This conflict was finally resolved by [[Roman the Great]] (1197–1205), who not only succeeded in uniting Galicia and Volhynia under his rule but also briefly extended his authority over [[Kiev]]. Roman's consolidation of power laid the groundwork for the rise of the Principality of Galicia–Volhynia, which became a significant political force in the region.<ref>{{cite encyclopedia|url=http://www.encyclopediaofukraine.com/display.asp?linkpath=pages\R\O\Romanovychdynasty.htm|title=Romanovych dynasty [Romanovyc]|publisher=Canadian Institute of Ukrainian Studies|encyclopedia=Encyclopedia of Ukraine|date=2001|access-date=26 December 2009}}</ref>

[[File:Галицько-Волинський літопис (2002).djvu|thumb|page=5|Fragment of a copy of the ''[[Galician–Volhynian Chronicle]]'', a literary work and historical source of the period]]
Following Roman's death, a period of unrest ensued, lasting until his son [[Daniel of Galicia|Daniel Romanovich]] reclaimed the throne in 1238. Daniel successfully restored his father's state, including Kiev. In 1240, the Mongol Empire, led by Batu Khan, unleashed devastating invasions across Kievan Rus'. Cities like Kiev were sacked, leaving much of the region in ruins. Daniel's decisive victory at the [[Battle of Yaroslavl (1245)|Battle of Yaroslavl]] in 1245 ended internal conflicts and firmly secured his control over the state. By 1246, Daniel was compelled to recognize Mongol supremacy to safeguard his state. Though this submission was humiliating, it allowed Daniel to retain some degree of autonomy, provided he paid tribute to the Mongol khan.{{sfn|Vernadsky|1970|p=144–149}}

Despite this subjugation, Daniel remained determined to free Ruthenia from Mongol dominance. He sought support from Western Europe, forging diplomatic ties with the [[Papacy]], [[Kingdom of Poland|Poland]], [[Kingdom of Hungary|Hungary]], and the [[Holy Roman Empire]]. In 1253, Daniel was crowned [[King of Ruthenia]] ({{Langx|la|Rex Rusiae}}) by a papal legate in [[Drohiczyn]], receiving formal recognition from [[Pope Innocent IV]]. This coronation symbolized Ruthenia's alignment with [[Western Europe]] and its Christian identity, while still adhering to the Orthodox faith. The crowning also carried the hope of an anti-Mongol alliance, though such a coalition never materialized due to political divisions in Western Europe.{{sfn|Magocsi|2010|p=126}} King Daniel also founded numerous cities that became hubs of trade, culture, and military strength. Among his most notable achievements were the establishments of [[Lviv]], named after his son Lev, and [[Chelm|Kholm]]. These urban centers not only revitalized the kingdom's economy but also helped Daniel consolidate his political authority over the region.<ref>[[Orest Subtelny]]. (1988) ''Ukraine: A History''. Toronto: University of Toronto Press, p62</ref><ref>Gloger, Zygmunt. ''[http://literat.ug.edu.pl/glogre/0037.htm Voivodeship of Ruthenia. Historic geography of old Polish lands (Województwo Ruskie. Geografia historyczna ziem dawnej Polski)] {{webarchive |url=https://web.archive.org/web/20180515232827/http://literat.ug.edu.pl/glogre/0037.htm |date=15 May 2018}}''. Library of Polish Literature POWRÓT.</ref>

After King Daniel Romanovych's death in 1264, the kingdom was inherited by his son, [[Leo I of Galicia|Lev Danylovych]]. Lev I ruled from 1269 to 1301 and relocated the capital from Kholm to Lviv. He continued his father's policies of defending the kingdom against external threats, particularly from the [[Mongols]], while also striving to maintain alliances with Poland and Lithuania to counterbalance Mongol influence. Although Lev managed to preserve the state's territorial integrity, the kingdom's power gradually eroded under the relentless pressure from the Mongol [[Golden Horde]] and ongoing internal political challenges.<ref>Котляр, М. Ф. ''[http://www.history.org.ua/?encyclop&termin=Lev_Danilovich Лев Данилович] {{Webarchive|url=https://web.archive.org/web/20160821235918/http://www.history.org.ua/?encyclop&termin=Lev_Danilovich |date=21 April 2016}}''</ref><ref>''Крип'якевич І. П''. Галицько-Волинське князівство.&nbsp;— Київ: Наукова думка, 1984.&nbsp;— С. 105.</ref> Following Lev's death in 1301, his son, [[Yuri I of Galicia|Yuri Lvovych]], ascended the throne and ruled until 1308. During his reign, Yuri I succeeded in maintaining relative stability, yet the kingdom's political position had significantly weakened compared to the time of Daniel. Despite his efforts, Yuri's reign was short-lived, and after his death, the kingdom entered a period of fragmentation.<ref>[http://chtyvo.org.ua/authors/Voitovych_Leontii/Yurii_Lvovych_i_ioho_polityka/ Войтович Л. (2001) Юрій Львович та його політика]. Галичина та Волинь у добу середньовіччя, до 800-річчя із дня народження Данила Галицького, Львів: Інститут українознавства ім. І. Крип'яквича НАН України.</ref>

[[File:Alex K Yuri Boleslav seal.png|left|thumb|upright=1.0|King's seal of Yuri Lvovych]]
Yuri's sons, [[Andrew of Galicia|Andrew]] and [[Leo II of Galicia|Lev II]], attempted to co-rule, but their efforts to sustain the kingdom's unity and strength ultimately failed. The Mongol Golden Horde continued to exert substantial influence over the weakened [[Kingdom of Ruthenia]] throughout the 14th century.<ref>Котляр М. Ф. ''[http://www.history.org.ua/index.php?termin=Andrij_Y Андрій Юрійович] {{Webarchive|url=https://web.archive.org/web/20160425163510/http://www.history.org.ua/index.php?termin=Andrij_Y |date=25 April 2016}}''</ref><ref>Котляр М. Ф. ''[http://resource.history.org.ua/cgi-bin/eiu/history.exe?Z21ID=&I21DBN=EIU&P21DBN=EIU&S21STN=1&S21REF=10&S21FMT=eiu_all&C21COM=S&S21CNR=20&S21P01=0&S21P02=0&S21P03=TRN=&S21COLORTERMS=0&S21STR=Lev_Yuriyovych Лев Юрійович] {{Webarchive|url=https://web.archive.org/web/20160425163510/http://www.history.org.ua/index.php?termin=Lev_Y |date=25 April 2016}}''</ref> After the deaths of the co-rulers around 1323, the kingdom found itself without strong leadership. [[Yuri II Boleslav]], the last ruler of the Kingdom of Ruthenia, took power following the demise of the Romanovych line. Reigning from 1323 to 1340, he was a member of the Polish [[Piast dynasty]], chosen as king due to his maternal connection to the Ruthenian royal family—his mother, [[Maria of Galicia|Maria]], was the daughter of Lev I.<ref name=Jasinski60>{{cite book |last=Jasiński |first=Kazimierz|title=Rodowód Piastów mazowieckich |year=1998 |publisher=Wydawnictwo Historyczne |location=Poznań - Wrocław |isbn=83-913563-0-2 |page=60 }}</ref> Upon ascending the throne, Boleslav converted to [[Eastern Orthodoxy|Orthodox Christianity]] and adopted the name Yuriy to garner support from the local Orthodox nobility. However, his reign was fraught with tension due to his [[Catholic]] background, which clashed with the predominantly Orthodox Ruthenian elite. During his rule, Yuriy II struggled to balance the competing interests of Poland, Lithuania, and the Mongol Golden Horde, while also introducing pro-Catholic policies that alienated the local nobility. His rule culminated in his assassination in 1340 by [[Ruthenians|Ruthenian]] nobles discontented with his leadership. His death triggered a fierce power struggle between Poland and Lithuania for control over the region. Soon after, [[Galicia (Eastern Europe)|Galicia]] was annexed by Poland, and [[Volhynia]] fell under Lithuanian rule, marking the end of the independent Kingdom of Ruthenia.<ref name=":Krypiakevich"/>

=== Foreign domination ===
{{Main|Grand Duchy of Lithuania|Crown of the Kingdom of Poland|Genoese Gazaria|Principality of Theodoro|Crimean Khanate}}
{{See also|Galicia–Volhynia Wars|Lithuanian Civil War (1432–1438)}}

From the 13th century onwards, parts of Ukraine’s [[Black Sea]] called [[Genoese Gazaria]] came under the influence of the [[Republic of Genoa]], which established fortified trading [[Genoese colonies|colonies]]. These included key settlements such as Caffa (modern [[Feodosia]]), Soldaia (modern [[Sudak]]), and others in today’s [[Odesa Oblast]]. These fortresses, heavily guarded by Genoese garrisons, functioned as hubs for maritime trade and ensured Genoa's control over Black Sea commerce. The Genoese dominance, however, faced challenges from neighboring powers and ended with the Ottoman conquest in 1475.<ref>{{Cite web |date=5 February 2018 |title=Генуэзские колонии в Одесской области - Бизнес-портал Измаила |url=http://izm-biz.info/genuezskie-kolonii-v-odesskoj-oblasti/ |access-date=19 September 2023 |archive-url=https://web.archive.org/web/20180205001115/http://izm-biz.info/genuezskie-kolonii-v-odesskoj-oblasti/ |archive-date=5 February 2018 }}</ref><ref>{{Cite web |title=О СОПЕРНИЧЕСТВЕ ВЕНЕЦИИ С ГЕНУЕЮ В XIV-м ВЕКЕ |url=https://www.vostlit.info/Texts/Dokumenty/Italy/venice/Veneto-genua/pred.phtml |access-date=19 September 2023 |website=www.vostlit.info}}</ref><ref>{{Cite web |date=26 March 2019 |title=Эпиграфические памятники Каффы {{!}} Старый музей |work=Старый музей &#124; Российский исторический музей |url=https://old-museum.org/halls/history_hall_20.htm |access-date=19 September 2023 |language=ru-RU}}</ref>

In 1322, [[Pope John XXII]] established a Catholic [[diocese]] in Caffa (modern-day [[Feodosia]]), marking the only Catholic stronghold within Mongol-controlled territories. It served as a central religious authority from the [[Balkans]] to the capital of the [[Golden Horde]], [[Sarai (city)|Sarai]]. The Genoese settlements were not only economic centers but also a point of cultural and religious interaction between [[Europe]], the [[Mongol Empire]], and the [[Middle East]].<ref>{{Cite book |last=Khvalkov |first=Evgeny |title=The colonies of Genoa in the Black Sea region: Evolution and transformation |date=2017 |isbn=978-1-351-62306-3 |page=69|location=New York |publisher= Routledge |oclc=994262849}}</ref>

[[File:Lithuanian state in 13-15th centuries.png|thumb|Map of the [[Grand Duchy of Lithuania]], at its greatest extent from the 13th to 15th centuries.]]
By the mid-14th century, the [[Grand Duchy of Lithuania]] expanded into the territories of modern [[Ukraine]]. After the decisive [[Battle of the Blue Waters]] against the Golden Horde (1362/63), Lithuania annexed [[Polotsk]], [[Volhynia]], [[Chernihiv]], and [[Kyiv]]. Lithuanian rulers adhered to the principle “We do not disturb the old, nor do we introduce the new”, which allowed local [[Ruthenians|Ruthenian]] (Ukrainian) traditions, religion, and administration to remain largely intact. The Lithuanian rulers styled themselves as “rulers of Rus’”, integrating Ruthenian traditions and governance into their system. This integration included Ruthenian aristocrats, like the [[Olelkovich|Olelkovich family]], who became influential in the Lithuanian administration. [[Old Church Slavonic]] and [[Ruthenian language|Ruthenian]] served as primary administrative languages alongside [[Latin]].<ref>{{Cite book |last=Millar |first=Robert |url=https://books.google.com/books?id=NGKJDAAAQBAJ |title=Authority and Identity: A Sociolinguistic History of Europe before the Modern Age |date=21 July 2010 |publisher=Springer |isbn=978-0-230-28203-2 |page=184 |language=en}}</ref>

Simultaneously, Poland began asserting influence over western Ukraine. [[Red Ruthenia]], parts of Volhynia, and [[Podolia]] were incorporated into the [[Kingdom of Poland]], and the Polish monarch adopted the title "lord and heir of Ruthenia" ({{Langx|la|Russiae dominus et Heres}}).<ref>{{Cite book |last=Voloshchuk |first=Myroslav |title=The Polish-Lithuanian Commonwealth: History, Memory, Legacy |series=The Principles of Ancient Rzeczpospolita Formation: The Medieval Ruthenian Dimension |editor-last=Chwalba |editor-first=Andrzej |editor-last2=Zamorski |editor-first2=Krzysztof}}</ref> Meanwhile, [[Kingdom of Hungary]] also maintained influence, particularly over [[Transcarpathia|Zakarpattia]] (Transcarpathia) and parts of [[Bessarabia]]. The [[Hungarian Crown]] controlled these regions, fostering [[Magyarization]] and [[Catholic Church|Catholic]] influence while integrating them into the Hungary’s political and economic system.<ref>{{Cite web|url=https://www.ukrainer.net/hungarians-of-ukraine/|title=Hungarians of Ukraine|date=21 August 2020 }}</ref>

Since the 14th century, Poland and Lithuania had developed a unique and evolving relationship, often defined by dynastic unions, military alliances, and shared geopolitical interests, particularly in countering external threats. These included the aggressive expansion of the [[Teutonic Knights]] in the [[Baltic region]] and the rise of the [[Principality of Moscow]] to the east. The need for mutual support in the face of these common enemies gradually led the two states toward closer cooperation. This relationship reached a decisive turning point with the [[Union of Krewo]] in 1385, which marked the beginning of a new political era. Through the marriage of [[Jadwiga of Poland]], the Queen of Poland, and [[Władysław II Jagiełło]], the Grand Duke of Lithuania, the Lithuanian Grand Duchy was brought under Polish influence. This union was not just a political arrangement but a dynastic consolidation, with Jagiełło converting to [[Christianity]] and agreeing to unite Lithuania with Poland under his rule. This union established the [[Jagiellonian dynasty]], which would go on to rule both Poland and Lithuania for several generations. The creation of this shared monarchy laid the foundation for an increasingly intertwined relationship between the two states, leading to greater cooperation in military, political, and cultural matters.<ref>{{citation |first=Norman |last=Davies |author-link=Norman Davies| title=[[God's Playground]]. A History of Poland. The Origins to 1795 |volume=I | publisher=Oxford University Press | year=2005 |isbn=978-0-19-925339-5 |edition=Revised}}</ref><ref>{{citation |first=Zenonas |last=Ivinskis |author-link=Zenonas Ivinskis |title=Lietuvos istorija iki Vytauto Didžiojo mirties |year=1978 |location=Rome |publisher=Lietuvių katalikų mokslo akademija |oclc=5075215 |language=lt}}</ref>

In the early 15th century, tensions within the [[Grand Duchy of Lithuania, Ruthenia and Samogitia]] over the governance of the Rus' lands intensified. These tensions escalated into a power struggle following the death of Grand Duke [[Vytautas]] in 1430. Vytautas had been a powerful and unifying figure, and his passing left a power vacuum that deepened divisions within the Lithuanian elite. Two main contenders for the throne emerged: [[Švitrigaila]], who had the support of the Orthodox Rus' nobility, and [[Sigismund Kęstutaitis]], who represented the Catholic Lithuanian elite.<ref name="NCMH">{{cite book| first=Aleksander |last=Gieysztor |author-link=Aleksander Gieysztor |title=The New Cambridge Medieval History, c.1415–c.1500 |chapter=The kingdom of Poland and the grand duchy of Lithuania, 1370–1506 |publisher= Cambridge University Press |year=1998 |isbn=0-521-38296-3 |volume=7 |chapter-url=https://books.google.com/books?id=Qzc8OeuSXFMC&pg=RA2-PA732 | pages=734–735}}</ref> In 1432, Sigismund Kęstutaitis declared himself the new [[Grand Duke of Lithuania]]. To consolidate his rule and gain favor with the Rus' lands, he proclaimed the creation of a new political entity—the {{ill|Grand Principality of Rus' (1432—1435)|uk|Велике князівство Руське (1432—1435)|vertical-align=sup}}. This new formation was intended to include several important regions, such as [[Volhynia]], [[Podolia]], [[Siveria]], [[Berestia]], and [[Dnieper Ukraine]], with [[Kyiv]] as its capital. Despite this declaration, Švitrigaila remained formally the head of the Grand Duchy of Lithuania and sought to transform the Rus' lands into an independent state under his control. His ambition to sever the ties with the rest of the Grand Duchy sparked a [[Lithuanian Civil War (1432–1438)|civil war]] that raged from 1432 to 1435, plunging Lithuania into internal conflict.<ref name=kiaupa>{{cite book | last1=Kiaupa | first1=Zigmantas |first2=Jūratė |last2=Kiaupienė |first3=Albinas |last3=Kuncevičius | title=The History of Lithuania Before 1795 | orig-year=1995 | edition=English | year=2000 | publisher=Lithuanian Institute of History | location=Vilnius | isbn=9986-810-13-2 | pages=205–211}}</ref>

[[File:Vilkamir battle monument — Помнік бітвы пад Вількамірам.Jpg|thumb|left|Monument at the field of the Battle of Wiłkomierz]]
Švitrigaila's forces, which included early [[Cossack]], sought external support from the [[Teutonic Order]], which had its own interests in weakening both Poland and Lithuania. The Teutonic Order's involvement further complicated the political situation. However, Sigismund Kęstutaitis found strong backing from [[List of Polish monarchs|Polish King]] [[Władysław II Jagiełło]] (Jogaila), as well as from the majority of the Lithuanian nobility. This external support proved pivotal in the conflict, tipping the scales in Sigismund's favor. The turning point in the war came with the [[Battle of Wiłkomierz]] (modern-day [[Ukmergė]], [[Lithuania]]) on 1 September 1435. This battle was one of the largest and most decisive military engagements in [[Eastern Europe]] during the 15th century. Švitrigaila's forces were decisively defeated, suffering a crushing blow that effectively ended the Grand Principality of Rus'. The defeat led to the collapse of Švitrigaila's short-lived state and ensured the continuation of Lithuanian rule over the Rus' lands. With the victory, Sigismund Kęstutaitis solidified his power as Grand Duke, and the Rus' territories were once again integrated into the Grand Duchy of Lithuania. However, these lands would now be firmly under Lithuanian control, with no 
significant autonomy for the Rus' people. The failure of the Grand Principality of Rus' also marked a significant shift in the governance of the region, as the aspirations of the Rus' nobility for greater independence were suppressed.<ref name=kiaupa/>

Southwestern Crimea saw the emergence of the [[Principality of Theodoro]], also known as Gothia, a Byzantine successor state. Centered in Doros (modern [[Mangup]]), Theodoro was a multi-ethnic entity populated by [[Greeks]], [[Goths]], [[Alans]], and others. Its rulers maintained close ties with the [[Byzantine Empire]] and the [[Empire of Trebizond]]. The principality acted as a buffer between Genoese colonies and the expanding [[Crimean Khanate]]. Despite its strong fortifications, Theodoro was conquered by the [[Ottoman Empire]] in 1475, as the Ottomans sought full dominance over the Black Sea region.<ref>[https://www.academia.edu/37968405/Dushenko_A._Byzantine_Weights_Excavated_at_Mangup_Византийские_разновесы_из_раскопок_Мангупа_ Dushenko A. Byzantine Weights Excavated at Mangup]</ref>

The increasing dominance of the Polish nobility over Ukrainian lands in the late 15th century sparked resistance, most notably [[Mukha Rebellion|Mukha’s Rebellion]] in 1490. Led by [[Petro Mukha]] and supported by Moldavian Prince [[Stephen the Great]], the uprising involved early [[Cossacks]], [[Hutsuls]], and [[Romanians|Romanians (Moldavians)]]. Mukha’s forces captured several towns in [[Pokuttya]] and advanced toward [[Lviv]], though they failed to take the city. The rebellion, while ultimately suppressed, revealed growing dissatisfaction among Ukrainians under foreign rule and foreshadowed future uprisings in the region.<ref name="Mukha's Rebellionn">{{Cite web|url=http://www.encyclopediaofukraine.com/display.asp?linkpath=pages%5CM%5CU%5CMukharebellion.htm|title=Mukha rebellion|website=www.encyclopediaofukraine.com}}</ref>

As the [[Golden Horde]] declined in the 15th century, the [[Crimean Khanate]] emerged as a dominant power in the [[Pontic–Caspian steppe|southern Ukrainian steppe]]. Centered around the city of [[Bakhchisarai]], the Khanate controlled much of the [[Black Sea]] coastline, including key ports and strategic territories in what is today southern Ukraine. This rise to power marked a significant shift in the region, as the Crimean Khanate not only played a key military and political role but also became a vital player in the economy of the Black Sea and beyond.<ref>Documents of the Crimean khanate from the collection of Huseyn Feyzkhanov / comp. and the transliteration. R. R. Abdujalilov; scientific. edited by I. Mingaleev. – Simferopol: LLC "Konstanta". 2017.  816 p. {{ISBN|978-5-906952-38-7}}</ref><ref>Sagit Faizov. Letters of khans Islam Giray III and Muhammad Giray IV to Tsar Alexey Mikhailovich and king Jan Kazimir, 1654–1658: Crimean Tatar diplomacy in polit. post-Pereyaslav context. time. Moscow: Humanitarii, 2003.  166 p. {{ISBN|5-89221-075-8}}</ref>

[[File:Ottoman empire 1481-1683.jpg|thumb|Map of the Crimean Khanate and the Ottoman Empire]]
From the early 16th century to the late 18th century, the Crimean Khanate was deeply involved in the region’s [[Crimean slave trade|slave trade]], which became one of its main economic drivers. The Khanate, often acting as an intermediary between the steppes and the [[Ottoman Empire]], exported an estimated 2 million slaves to [[slavery in the Ottoman Empire]] and [[History of slavery in the Muslim world|the Middle East]] between 1500 and 1700. These slaves, many of whom were captured in raids on neighboring lands, were primarily sold to the Ottoman Empire, where they were used in various sectors, including the military, households, and harems.<ref>Darjusz Kołodziejczyk, as reported by {{cite journal |author=Mikhail Kizilov |title=Slaves, Money Lenders, and Prisoner Guards:The Jews and the Trade in Slaves and Captivesin the Crimean Khanate |url=https://www.academia.edu/3706285 |journal=The Journal of Jewish Studies|year=2007|volume=58 |issue=2 |pages=189–210 |doi=10.18647/2730/JJS-2007 }}</ref>

Despite its growing power, the Crimean Khanate remained a [[vassal state]] of the Ottoman Empire throughout much of its history. This relationship provided the Khanate with military support and protection, but also limited its autonomy. The Crimean Khanate’s role as a vassal did not diminish its influence, however, and it continued to exert significant control over the Black Sea region until the late 18th century.<ref>{{cite web |author=Brian Glyn Williams |title=The Sultan's Raiders: The Military Role of the Crimean Tatars in the Ottoman Empire |url=http://www.jamestown.org/uploads/media/Crimean_Tatar_-_complete_report_01.pdf |work=[[The Jamestown Foundation]] |year=2013 |page=27 |url-status=dead |archive-url=https://web.archive.org/web/20131021092115/http://www.jamestown.org/uploads/media/Crimean_Tatar_-_complete_report_01.pdf |archive-date=21 October 2013 |author-link=Brian Glyn Williams }}</ref>